JP2601125Y2 - Flat cam mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat cam mechanism in which an outer ring is in contact with the outer periphery of a cam and rolls.

[0002]

2. Description of the Related Art As this type of planar cam mechanism, there is a follower cam follower or roller follower having an outer ring that rolls while being in contact with the outer periphery of a cam. The reciprocating mechanism is operated using the change in distance. By the way, the rotation speed (rotation speed) of the outer ring that rolls on the outer periphery of the cam of the cam follower or the roller follower is approximately equal to the maximum rotation radius (Rm ) of the cam.
ax) takes the maximum value when approaching the portion, and takes the minimum value when approaching the minimum rotation radius (Rmin) of the cam. That is, the rotation speed of the outer ring of the cam follower
Varies depending on the radius of rotation R of the cam peripheral position,
Is done.

[0003] At this time , the required speed required for accelerating or decelerating the rotation speed of the outer ring of the cam follower or the roller follower.
The torque, that is, the rotation speed of the outer ring is changed from Nmin to Nma.
It is known that the torque T required to accelerate (decelerate) to x is represented by the following equation 1.

[0004]

(Equation 1) At this time, Nmax = N × 2Rmax / d, Nmin =
N × 2Rmin / d, where N is the cam rotation speed (rp
m), GD ² (Gee disk air) is the amount of inertia of the outer ring
Which mechanically has the same meaning as the moment of inertia I.
It indicates the difficulty of turning an object.
You. GD ² = 4g × I, (where g represents gravitational acceleration
You. ) D is the outer ring of the cam follower or roller follower
Shows the diameter of In the case GD ² is the rolling elements interposed between the outer ring and the shaft is added to 1/4 of the GD ^2. In addition, t is the arrival time from Rmax to Rmin, and C is a coefficient value that differs depending on the motion curve and takes a value of 2 or more. Ma
The required torque T is a static torque caused by the contact between the outer ring and the cam.
The driving torque is given by the stopping friction force.

[0005]

An invention is, however, such conventional flat cam mechanism, and try to consider the partial status mosquito Muforoa or roller follower, a sudden change in the rotational speed of the cam follower or roller follower outer ring As a result, the required torque is increased,
The torque required to accelerate and decelerate the rotation speed increases,
When the driving torque cannot be satisfied, the rolling of the outer ring cannot follow completely, and the contact state between the cam and the outer ring changes from rolling contact to partial sliding contact. Also, such slippage is of course if the acceleration is large, external
Relatively small when the wheel is the GD ² increases in size
It is generated even when acceleration / deceleration is large .

[0006] When the slip occurs, abnormal wear is generated between the cam and the outer ring, and at the same time, impulsive sound and vibration are generated simultaneously, so that mechanical performance, particularly dynamic accuracy, is remarkably reduced. there were.

In view of the above-mentioned problems, the present invention provides a cam and an outer ring integrally provided with a gear, and rolls the outer ring around the cam in a state where the respective gears are meshed with each other. It is an object of the present invention to provide a planar cam mechanism that eliminates slippage between a wheel and an outer ring.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a flat cam mechanism having an outer ring that rolls while being in contact with the outer periphery of a cam. A cam-side gear and an outer-ring-side gear whose pitch circle is the outer periphery of the cam and the outer-ring are integrally provided, and the cam and the outer ring are brought into contact with each other, and the cam-side gear and the outer-ring-side gear are meshed with each other. It consists of.

[0009]

According to the planar cam mechanism of the present invention having the above construction, when the outer ring is in contact with the outer periphery of the cam, the cam side gear and the outer ring side gear are integrally provided on the sides of the cam and the outer ring. Are engaged, so the rotation speed of the outer ring
Needed to accelerate or decelerate the rotation speed due to sudden changes in
Required torque increases and is generated by the contact between the outer ring and the cam
When the driving torque due to static friction
Change of the radius of rotation of the cam with which the outer ring contacts
The outer ring moves up and down in the radial direction, and the contact force with the cam
Changes, even if the static friction force changes,
Drive torque is applied by the engagement of the cam side gear and the outer ring side gear.
As a result, it is possible to reliably prevent the outer ring from slipping.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of the flat cam mechanism of the present invention. FIG. 1 is a sectional side view and FIG. 2 is a front view.

1 and 2, reference numeral 10 denotes a cam follower or a roller follower as a flat cam mechanism. Hereinafter, the flat cam mechanism will be described as a roller follower 10, but the same applies to a cam follower. The roller follower 10 includes a non-circular cam 12 and a circular outer ring 14 abutting on the outer periphery 12 a of the cam 12. The cam 12 is rotated about the rotation axis O1, and the outer ring 14 is
6 is rotatably attached via a needle bearing 18, and is rotated about this rotation shaft 16.

A cam gear 20 is integrally fixed to one side of the cam 12 (right side in FIG. 1).
The outer ring gear 22 is integrally provided on the same direction side (right side in FIG.
Is formed. The cam-side gear 20 is formed in a non-circular shape along the outer shape of the cam 12, and the pitch circle P 1 of the tooth portion 20 a coincides with the outer periphery of the cam 12. The outer ring gear 22 is formed in a circular shape along the outer shape of the outer ring 14, and the pitch circle P2 of the teeth 22a is made to coincide with the outer periphery of the outer ring 14. The cam gear 20 and the outer gear 22 are meshed with each other in a state where the outer ring 14 is in contact with the outer peripheral surface 12 a of the cam 12.

The cam 12 and the outer ring 14 are urged toward each other by urging means (not shown), and the outer ring 14 is brought into contact with the outer periphery 12a of the cam 12 with an appropriate pressing force. The cam-side gear 20 is formed as an unequal-speed gear, and there may be some play at the meshing portion between the cam-side gear 20 and the outer ring-side gear 22.

In the roller follower 10 according to the present embodiment, when the cam 12 and the outer ring 14 come into contact with a predetermined pressing force, the cam 12 and the outer ring 1 have the same configuration.
4 and a cam-side gear 20 integrally provided on one side of each
And the outer ring gear 22 mesh with each other, so that the outer ring 1
4 rolls on the outer peripheral surface 12a of the cam 12 while maintaining the meshing state of the respective gears 20 and 22. Therefore, the outer ring 14
Since the distance from the rotation center O1 of the cam 12 changes with the rotation of the non-circular cam 12, the rotation center O
The revolving shaft 16 of the outer ring 14 is reciprocated with respect to 1.

By the way, since the cam side gear 20 and the outer ring gear 22 in the contact between the cam 12 and the outer ring 14 as described above in this embodiment are engaged with each other, the outer ring 14 times
The sudden change in the rotation speed causes the rotation speed to accelerate or decelerate.
Torque required for the outer ring 14 and the cam 12
Can be covered by drive torque due to static friction generated by contact with
The cam 12 around which the outer ring 14 is in contact.
Outer ring 14 moves up and down in the radial direction
As a result, the contact force with the cam 12 changes, and the static friction force
Is changed, the driving torque is given by the engagement between the cam-side gear 20 and the outer-ring-side gear 22, and the cam 12
And the outer ring 14 can be reliably prevented from slipping. Therefore, by preventing slippage in this way,
It is possible to prevent abnormal wear from occurring between the cam 12 and the outer race 14, and to prevent impact noise, vibration, and the like, thereby significantly improving mechanical performance, particularly dynamic accuracy.

[0016]

As described above, in the flat cam mechanism according to the present invention, the cam and the outer ring gear provided on the side of the cam and the outer ring are meshed with each other and the outer periphery of the cam is engaged. since abut the outer ring on the surface, of the outer ring
Accelerates or decelerates rotation speed due to sudden change in rotation speed
The required torque required for
When the driving torque cannot be covered by the static friction generated by contact
Change in the radius of rotation of the cam around which the outer ring is in contact.
, The outer ring moves up and down in the radial direction,
When the contact force changes and the static friction force changes,
Even when the cam gear and the outer ring gear mesh, the drive torque
Therefore, it is possible to reliably prevent the occurrence of slip on the outer ring due to the application of friction. Therefore, various excellent effects of preventing abnormal wear between the cam and the outer race, impact noise and vibration, etc., and greatly improving mechanical performance, particularly dynamic accuracy, are achieved.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing an embodiment of a flat cam mechanism according to the present invention.

FIG. 2 is a front view showing an embodiment of the flat cam mechanism according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Roller follower (plane cam mechanism) 12 Cam 14 Outer ring 20 Cam side gear 22 Outer ring side gear P1, P2 Pitch circle

Claims (1)

(57) [Scope of request for utility model registration] 1. A planar cam mechanism having an outer ring which rolls while being in circumferential contact with the outer periphery of a cam. A flat cam mechanism, wherein an outer ring gear is integrally provided, the cam and the outer ring abut on each other, and the cam gear and the outer ring gear are meshed with each other.